1. Field of the Invention
The present invention relates to a sheet treating apparatus and an image forming apparatus provided therewith.
2. Related Background Art
In an image forming apparatus such as a copying apparatus, a printer, a facsimile or a multi-functional composite equipment thereof, there is known an apparatus in which a main body of the image forming apparatus is provided with a sheet treating apparatus for applying a treatment such as a stapling onto a sheet discharged from such main body after an image formation.
Such sheet treating apparatus conveys sheets discharged from the main body of the image forming apparatus to a sheet treating portion, then executing a sheet stack aligning operation for stacking and aligning such discharged sheets and a treatment such as a stapling operation for stapling the sheets, and, after such treatments, discharging sheets or a stack of sheets (hereinafter called sheet stack (bundle)) to a stack tray (sheet stacking device).
Also the sheet treating apparatus is generally provided at a lateral side of the main body of the image forming apparatus, but there is known a configuration in which a main body of the sheet treating apparatus is positioned above an image forming portion so as not to exceed the area of the image forming apparatus, thereby achieving a space saving (for example cf. Japanese Patent Application Laid-Open No. 2001-72311).
However, as such prior sheet treating apparatus is provided with only one stacking tray, in case such sheet treating apparatus is accommodated in a recent composite printer having various modes (functions) such as a copying machine, a printer, a facsimile and the like, the sheets outputted in correspondence with (or in association with) the modes of copying, printing, facsimile and the like are discharged and stacked on a same stacking tray.
When the sheets outputted in correspondence with various modes are stacked on a same stacking tray, it becomes difficult to identify (distinguish) that the stacked sheets were respectively outputted in which modes, so that the needs of the users cannot be satisfied.